A homeopathic repertory is a reference manual used to find the appropriate treatment for a medical condition. The repertory, which is used in homeopathy training, is an index of symptoms categorically arranged in such a way that the user can quickly find what they are looking for. Every category — also called a rubric — has a number of homeopathic remedies that are known for treating the symptom.
As an example of how a homeopathic repertory might be used, an individual suffering from headaches that occur in the front of the head, especially in the morning hours would use the homeopathic repertory to look up the part of the body where the pain is — in this case, the head. Under the subsection "pain," the user would look under "frontal," then "worse in the morning." A list of homeopathic remedies targeted to relieve that specific type of pain would be found listed next to the symptom. Names of the remedies are usually abbreviated; such as "arn" for Arnica montana and "sulph" for sulphur.
More detailed information about each of the possible remedies can then be obtained from a materia medica. This is a reference text listing thousands of herbal and mineral remedies in alphabetical order, describing the homeopathic effects of each drug. A repertory and a materia medica are to be used together, and they complement one another.
Often the most difficult part of using a homeopathic repertory is in the symptom selection. An incorrect selection of symptoms can lead to using a remedy that simply does not work because the remedy wasn't an exact match for the patient's symptoms. In homeopathic medicine, there can be only one correct remedy at a time for any symptom.
The remedies included in a homeopathic repertory must meet a high standard of established effectiveness through proving and clinical experience. Just as with conventional medical journals and physician's desk reference manuals, errors can and do occur, however. These errors are continually being corrected in revised editions of the homeopathic repertory. Debate among homeopaths regarding the inclusion of or proven effects of any given remedy in a repertory is continually a hot topic within the homeopathic healthcare community.
Serious students and practitioners of homeopathy usually have several different repertory books in their libraries. In the 1980s and '90s, repertories were computerized into databases, speeding up the search process considerably. Internet repertory databases now make it possible to refine one's search using certain criteria that gives more weight to some rubrics and less weight to other rubrics.